Vincenzo Montella's men go into the second leg holding the advantage of an away goal following a 1-1 draw in the first leg in Ukraine.
But the Serie A outfit also approach the contest in disappointing form having failed to win in their last four matches.
Monday's 1-0 home loss to Verona - in which they conceded a 90th-minute winner - saw Fiorentina drop out of the Europa League qualification places for next season.
Success in the Europa League would ensure a place in next year's UEFA Champions League and render Fiorentina's league position immaterial in that respect.
And Pasqual told the club's official website: "We had closed Verona out, but in the end we left them space to mount a counter attack where they played to their strengths.
"We will need everyone to be here at the end. We want to move forward in the Europa League. Everyone would like to see us win the game.
"We continue to work. We always want to win. We must go through for sure. We have to react. We have to get onto the field to win Thursday. With Dynamo [we] will play our game."
Fiorentina sustained some new injury problems in the reverse against Verona, with striker Khouma El Babacar - scorer of a last-gasp equaliser in the first leg - suffering a twisted knee and midfielder Milan Badelj bruising his nose.
David Pizarro is also a doubt with a thigh complaint, while Dynamo are without the suspended Aleksandar Dragovic, who may be joined on the sidelines by injured midfielder Miguel Veloso.
Dynamo are seeking to go one better than in the 2008-09 UEFA Cup, when they progressed to the last four only to lose to domestic rivals and eventual winners Shakhtar Donetsk over two legs.
But Sergei Rebrov's men are five points clear of Shakhtar in the Ukrainian Premier League and have not lost since their first-leg defeat to Everton in the round of 16.
Artem Kravets scored a double in Dynamo's 3-1 win at Volyn at the weekend and he told Dynamo's official site: "Of course Fiorentina have weaknesses, and we will try to use them.
"I will not go into details, not to show our hand before the decisive game. But believe me, we are prepared for this game."
‘Arteta, Alonso, Emery, me… none of us were physical players – we needed the understanding of the game. That probably helped us move into management’: Premier League boss reveals reasons for natural career progression
‘England have the players to win the World Cup – it’ll be tough for Thomas Tuchel to do a bad job, with the squad he has at his disposal’ Former Three Lions winger backs new boss after gentle qualifying draw
